Heat exchanger

ABSTRACT

A heat exchanger for a motor vehicle, with a housing with a first housing side and with a second housing side opposite to the first housing side, and with an inner housing wall and with an outer housing wall. The tubes, through which a gas can flow, are disposed in the housing. The tubes each of which has a first tube end and a second tube end, opposite to the first tube end, and with a first tube sheet disposed in the area of the first housing side. A first tube sheet has a number of first through-openings, through which the first tube ends extend, and a second tube sheet disposed in the area of the second housing side that has a number of second through-openings through which the second tube ends extend. The first tube sheet forms a first plane and the second tube sheet forms a second plane.

This nonprovisional application claims priority under 35 U.S.C. §119(a) to German Patent Application No. 10 2015 210 942.9, which was filed in Germany on Jun. 15, 2015, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a heat exchanger, in particular an exhaust gas heat exchanger or a charge air cooler, in particular for a motor vehicle.

Description of the Background Art

Exhaust gas heat exchangers are used in motor vehicles, for example, in so-called exhaust gas recirculation systems. In this case, the exhaust gas is cooled and, inter alia, there is a reduction of the pollutants arising during fuel combustion, as well as a lower fuel consumption.

DE 199 07 163 C2 discloses an exhaust gas heat exchanger with tubes, held at both ends in tube sheets, for conducting a gas and with a housing, connected to the tube sheets and surrounding the tubes, for conducting a liquid coolant. In this case, the tube sheets, the tubes, and the housing are made of austenitic heat-resistant steel sheets. The tubes are welded into the tube sheets stamped out of a metal sheet and the housing is welded to the tube sheets.

DE 10 2010 025 030 B4 discloses a heat exchanger for an internal combustion engine, which is to be used, for example, for cooling an exhaust gas stream intended for exhaust gas recirculation. The heat exchanger here has a base tube formed by two interconnected deep-drawn pots. The two ends of the base tube each have a tube sheet, whereby the individual tube sheets are a single-part component of the deep-drawn pots. A tube bundle extends between the two tube sheets within the base tube.

In particular, the type of insertion and/or pressing in of the deep-drawn pots serving as tube sheets, actions which are often taken during the fabrication of the heat exchanger, in the deep-drawn direction has the result that the complete length of the base tube or of the housing of the heat exchanger cannot be utilized as a heat exchanging region. The exhaust gas-carrying tubes disposed in the base tube or in the housing of the heat exchanger are in each case shorter by the deep-drawing height than the base tube or the housing of the heat exchanger.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a heat exchanger, which is improved relative to the prior art and makes available a higher heat transfer rate.

An exemplary embodiment of the invention relates to a heat exchanger, in particular to an exhaust gas heat exchanger or a charge air cooler for a motor vehicle, with a housing with a first housing side and with a second housing side, opposite to the first housing side, and with an inner housing wall and with an outer housing wall, whereby tubes, through which a gas can flow, are disposed in the housing, said tubes each of which has a first tube end and a second tube end, opposite to the first tube end, and with a first tube sheet disposed in the area of the first housing side, whereby the first tube sheet has a number of first through-openings, through which the first tube ends extend, and with a second tube sheet disposed in the area of the second housing side, whereby the second tube sheet has a number of second through-openings through which the second tube ends extend, whereby the first tube sheet forms a first plane and the second tube sheet forms a second plane, whereby the first tube sheet has a first circumferential edge raised at a first angle a from the first plane and the second tube sheet has a circumferential second edge raised at a second angle 13 from the second plane, whereby the first edge in the area of the first housing side is connected to the inner housing wall or in the area of the first housing side to the outer housing wall and/or the second edge in the area of the second housing side is connected to the inner housing wall or in the area of the second housing side to the outer housing wall. This design form in an advantageous way allows an effective heat transfer over the entire length of the housing between the exhaust gas stream carried in the tubes and a cooling medium flowing around the tubes within the housing. In this case, ‘extend’ can mean that the tube coming from one side at least engages in the through-opening and optionally emerges again out of the through-opening on the opposite side.

In an exemplary embodiment of the heat exchanger, the first edge can have a first contact side and a second contact side opposite to the first contact side, whereby the first contact side in the area of the first housing side is connected to the inner housing wall or the second contact side in the area of the first housing side is connected to the outer housing wall.

The heat exchanger at the second edge can have a first contact area and a second contact area opposite to the first contact area, whereby the first contact area in the area of the second housing side is connected to the inner housing wall or the second contact area in the area of the second housing side is connected to the outer housing wall. The tube sheets advantageously can be connected to the housing in this way, without the first edge or the second edge reducing the space available for the heat transfer.

An embodiment of the heat exchanger provides that the tubes are arranged substantially lying parallel next to one another in the longitudinal direction such that gaps through which a coolant can flow are formed between the tubes. The relation of the exhaust gas amount and the heat transfer performance can be varied by varying the gap depth.

In an exemplary embodiment of the heat exchanger, the first contact side and/or the second contact side and/or the first contact area and/or the second contact area can be connected to the inner housing wall and/or the outer housing wall with solder. This facilitates the production of the heat exchanger in a bundling and soldering process.

In an exemplary embodiment of the heat exchanger, the first contact side and/or the second contact side and/or the first contact area and/or the second contact area can be connected to the inner housing wall and/or the outer housing wall substantially by material bonding. As a result, an especially strong connection between the tube sheets and the housing is possible, which facilitates the application of pressure during the operation of the heat exchanger.

In an embodiment of the heat exchanger, the first tube ends in the area of the first through-openings can be connected to the first tube sheet by solder and the second tube ends in the area of the second through-openings are connected to the second tube sheet by solder. The production of the heat exchanger by a bundling and soldering process is also simplified as a result.

An embodiment of the heat exchanger provides that the first through-openings and/or the second through-openings each have passages through which the first tube ends and/or the second tube ends extend. The fabrication is considerably simplified as a result and a higher stability of the heat exchanger in the area of the first housing side and the second housing side is achieved.

In an embodiment of the heat exchanger, the housing can have an inlet opening for a coolant supply and/or an outlet opening for coolant removal.

In further exemplary embodiments of the heat exchanger, the tubes are formed as flat tubes, and/or turbulence inserts and/or spacers and/or corrugated fins are arranged between the tubes, and/or the tubes have a substantially smooth surface and/or a substantially circular cross section.

In an exemplary embodiment of the heat exchanger, a bypass channel can be located in the area of the housing. This permits control of the exhaust gas amount that is conveyed through the heat transfer region of the heat exchanger.

An embodiment of the heat exchanger provides that the first tube sheet and the second tube sheet are produced in a deep-drawing process. This is an especially cost-efficient production method for the tube sheets.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes, combinations and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 shows a schematic side view of a heat exchanger of the invention;

FIG. 2 shows a perspective view of the heat exchanger according to FIG. 1,

FIG. 3 shows a schematic detailed view of a part of the heat exchanger according to FIG. 1;

FIG. 4 shows a schematic detailed view of a further part of the heat exchanger according to FIG. 1;

FIG. 5 shows a schematic side view of a further exemplary embodiment of a heat exchanger;

FIG. 6 shows a perspective view of the heat exchanger according to FIG. 5;

FIG. 7 shows a schematic detailed view of a part of the heat exchanger according to FIG. 5; and

FIG. 8 shows a schematic detailed view of a further part of the heat exchanger according to FIG. 5.

DETAILED DESCRIPTION

FIGS. 1 and 2 show an exemplary embodiment of heat exchanger 1 of the invention. Heat exchanger 1 is disposed by way of example as an exhaust gas heat exchanger in an exhaust gas recirculation system of a motor vehicle. Alternatively, heat exchanger 1 can also be disposed as a charge air cooler in an exhaust gas recirculation system of a motor vehicle. Moreover, heat exchanger 1 can also be disposed elsewhere.

Heat exchanger 1 has a housing 2. Housing 2 is made substantially as a type of tubular shell body, for example, of sheet steel and has an inner housing wall 5 and an outer housing wall 6.

Housing 2 at its end has a first housing side 3 and an end-side, second housing side 4 opposite to first housing side 3. On the circumferential side, housing 2 has an inlet opening 21 and an outlet opening (not shown). A housing interior, substantially delimited by inner housing wall 5, is fluidically connected to a coolant circuit via inlet opening 21 and the outlet opening. In this case, a substantially liquid coolant flows into the housing interior through inlet opening 21 and out of the housing interior through the outlet opening.

In the area of the housing interior, a number of tubes 7 are arranged parallel to one another and parallel to the longitudinal direction of housing 2. Tubes 7 have a first tube end 8, which is disposed in the area of first housing side 3, and a second tube end 9, which is disposed in the area of second housing side 4. Tubes 7 are made, for example, as flat tubes. In alternative embodiments, tubes 7 may also have a substantially circular cross section.

In the area of first housing side 3, a first tube sheet 10 is arranged substantially perpendicular to the longitudinal axis of housing 2. First tube sheet 10 has a number of first through-openings 11, which are arranged vertically to the longitudinal direction of housing 2 and are penetrated by first tube ends 8.

In the area of second housing side 4, a second tube sheet 12 is arranged substantially perpendicular to the longitudinal axis of housing 2. Second tube sheet 12 has a number of second through-openings 13, which are arranged vertically to the longitudinal direction of housing 2 and are penetrated by second tube ends 9.

First through-openings 11 and second through-openings 13 can have passages. First tube ends 8 can be soldered to first tube sheet 10 in the area of first through-openings 11. Second tube ends 9 can be soldered to second tube sheet 12 in the area of second through-openings 13.

For example, an exhaust gas stream, discharged by the internal combustion engine of the motor vehicle, flows through tubes 7. The exhaust gas stream flows into tubes 7, for example, in the area of first tube ends 8 and flows out of tubes 7 in the area of second tube ends 9 and is then supplied to an intake tract of the internal combustion engine.

Tubes 7 are arranged spaced apart from one another such that gaps 20 are arranged between them. Coolant flows through gaps 20. Coolant flows around tubes 7. In this case, heat is transferred from the exhaust gas to the coolant and the exhaust gas is cooled at least partially by the coolant.

In exemplary embodiments in which heat exchanger 1 is formed as a charge air cooler, charge air flows through tubes 7 and is cooled by the coolant.

Tubes 7 have a surface on which in the exemplary embodiment shown in FIGS. 1 and 2 spacers 22 are arranged. In alternative exemplary embodiments, turbulence inserts and/or corrugated fins as well can be arranged on the surface of tubes 7 and/or between tubes 7 in the area of gaps 20. An exemplary embodiment of heat exchanger 1, which has tubes 107 with a smooth surface 123, is shown in FIGS. 5 and 6.

First tube sheet 10 in the exemplary embodiment shown in FIGS. 1 and 2 in the area of first housing side 3 forms a first plane arranged perpendicular to the longitudinal direction of housing 2. First tube sheet 10 has a circumferential first edge 14 raised at a first angle a from the first plane.

A detailed illustration of first edge 14 of the exemplary embodiment, shown in FIGS. 1 and 2, of heat exchanger 1 is shown in FIG. 3. First edge 14 has a first contact side 16 and a second contact side 17 opposite to first contact side 16. First contact side 16 is connected to inner housing wall 5 in the area of first housing side 3. In this case, first contact side 16 and inner housing wall 5 can be connected in particular with solder and/or by material bonding. For the sake of clarity, first contact side 16 and inner housing wall 5 as well as tubes 7 and first tube sheet 10 are shown spaced apart from one another.

Second tube sheet 12 in the exemplary embodiment shown in FIGS. 1 and 2 in the area of second housing side 4 forms a second plane arranged perpendicular to the longitudinal direction of housing 2. Second tube sheet 12 has a circumferential second edge 15 raised at a second angle 13 from the second plane.

A detailed illustration of second edge 15 of the exemplary embodiment, shown in FIGS. 1 and 2, of heat exchanger 1 is shown in FIG. 4. Second edge 15 has a first contact area 18 and a second contact area 19 opposite to first contact area 18. First contact area 18 is connected to inner housing wall 5 in the area of second housing side 4. In this case, first contact area 18 and inner housing wall 5 can be connected in particular with solder and/or by material bonding. For the sake of clarity, first contact area 18 and inner housing wall 5 as well as tubes 7 and second tube sheet 12 are shown spaced apart from one another.

FIGS. 5 and 6 show a further exemplary embodiment of a heat exchanger 101 of the invention. Heat exchanger 101 is disposed by way of example as an exhaust gas heat exchanger in an exhaust gas recirculation system of a motor vehicle. Alternatively, heat exchanger 101 can also be disposed as a charge air cooler within an exhaust gas recirculation system of a motor vehicle. Moreover, heat exchanger 101 can also be disposed elsewhere.

Heat exchanger 101 has a housing 102. Housing 102 is made substantially as a type of tubular shell body, for example, of sheet steel and has an inner housing wall 105 and an outer housing wall 106.

Housing 102 at its end has a first housing side 103 and an end-side, second housing side 104 opposite to first housing side 103. On the circumferential side, housing 102 has an inlet opening 121 and an outlet opening (not shown). A housing interior, substantially delimited by inner housing wall 105, is fluidically connected to a coolant circuit via inlet opening 121 and the outlet opening. In this case, a substantially liquid coolant flows into the housing interior through inlet opening 121 and out of the housing interior through the outlet opening.

In the area of the housing interior, a number of tubes 107 are arranged parallel to one another and parallel to the longitudinal direction of housing 102. Tubes 107 have a first tube end 108, which is disposed in the area of first housing side 103, and a second tube end 109, which is disposed in the area of second housing side 104. Tubes 107 are made, for example, as flat tubes. In alternative embodiments, the tubes may also have a substantially circular cross section.

In the area of first housing side 103, a first tube sheet 110 is arranged substantially perpendicular to the longitudinal axis of housing 102. First tube sheet 110 has a number of first through-openings 111, which are arranged vertically to the longitudinal direction of housing 102 and are penetrated by first tube ends 108. In the area of second housing side 104, a second tube sheet 112 is arranged substantially perpendicular to the longitudinal axis of housing 102. Second tube sheet 112 has a number of second through-openings 113, which are arranged vertically to the longitudinal direction of housing 102 and are penetrated by second tube ends 109.

First through-openings 111 and second through-openings 113 can have passages. First tube ends 108 can be soldered to first tube sheet 110 in the area of first through-openings 111. Second tube ends 109 can be soldered to second tube sheet 112 in the area of second through-openings 113.

For example, an exhaust gas stream, discharged by the internal combustion engine of the motor vehicle, flows through tubes 107. The exhaust gas stream flows into tubes 107, for example, in the area of first tube ends 108 and flows out of tubes 107 in the area of second tube ends 109 and is then supplied to an intake tract of the internal combustion engine.

Tubes 107 are arranged spaced apart from one another such that gaps 120 are arranged between them. Coolant flows through gaps 120. Coolant flows around tubes 107. In this case, heat is transferred from the exhaust gas to the coolant and the exhaust gas is cooled at least partially by the coolant.

In exemplary embodiments in which heat exchanger 101 is formed as a charge air cooler, charge air flows through tubes 107 and is cooled by the coolant.

Tubes 107 have a smooth surface 123. In alternative embodiments, spacers may be arranged on the surface of tubes 107 and/or turbulence inserts and/or corrugated fins may be arranged on the surface of tubes 107 and/or between tubes 107 in the area of gaps 120.

First tube sheet 110 in the exemplary embodiment shown in FIGS. 5 and 6 in the area of first housing side 103 forms a first plane arranged perpendicular to the longitudinal direction of housing 102. First tube sheet 110 has a circumferential first edge 114 raised at a first angle a from the first plane.

A detailed illustration of first edge 114 of the exemplary embodiment, shown in FIGS. 5 and 6, of heat exchanger 101 is shown in FIG. 7. First edge 114 has a first contact side 116 and a second contact side 117 opposite to first contact side 116. Second contact side 117 is connected to outer housing wall 106 in the area of first housing side 103. In this case, second contact side 117 and outer housing wall 106 can be connected in particular with solder and/or by material bonding. For the sake of clarity, second contact side 117 and outer housing wall 106 as well as tubes 107 and second tube sheet 112 are shown spaced apart from one another.

Second tube sheet 112 in the exemplary embodiment shown in FIGS. 5 and 6 in the area of second housing side 104 forms a second plane arranged perpendicular to the longitudinal direction of housing 102. Second tube sheet 112 has a circumferential second edge 115 raised at a second angle 13 from the second plane.

A detailed illustration of second edge 115 of the exemplary embodiment, shown in FIGS. 5 and 6, of heat exchanger 101 is shown in FIG. 8. Second edge 115 has a first contact area 118 and a second contact area 119 opposite to first contact area 118. Second contact area 119 is connected to outer housing wall 106 in the area of second housing side 104. In this case, second contact area 119 and outer housing wall 106 can be connected in particular with solder and/or by material bonding. For the sake of clarity, second contact side 119 and outer housing wall 106 as well as tubes 107 and second tube sheet 112 are shown spaced apart from one another.

The exemplary embodiments shown in FIGS. 1, 2, 5, and 6, moreover, have a circumferential flange 24 or a circumferential flange 124.

Tube sheets 10, 12, 110, and 112, shown in FIGS. 1, 2, 5, and 6, can be fabricated in particular as deep-drawn pots.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims. 

What is claimed is:
 1. A heat exchanger comprising: a housing with a first housing side and a second housing side opposite to the first housing side and with an inner housing wall and an outer housing wall; tubes through which a gas is adapted to flow, the tubes being arranged in the housing, the tubes each have a first tube end and a second tube end opposite to the first tube end; a first tube sheet arranged in an area of the first housing side, the first tube sheet having a plurality of first through-openings through which the first tube ends extend; and a second tube sheet arranged in an area of the second housing side, the second tube sheet having a plurality of second through-openings through which the second tube ends, wherein the first tube sheet forms a first plane and the second tube sheet forms a second plane, wherein the first tube sheet has a first circumferential edge raised at a first angle from the first plane and the second tube sheet has a circumferential second edge raised at a second angle from the second plane, and wherein the first edge in the area of the first housing side is connected to the inner housing wall or in the area of the first housing side to the outer housing wall and/or wherein the second edge in the area of the second housing side is connected to the inner housing wall or in the area of the second housing side to the outer housing wall.
 2. The heat exchanger according to claim 1, wherein the first edge has a first contact side and a second contact side opposite to the first contact side, wherein the first contact side in the area of the first housing side is connected to the inner housing wall or the second contact side in the area of the first housing side is connected to the outer housing wall.
 3. The heat exchanger according to claim 1, wherein the second edge has a first contact area and a second contact area opposite to the first contact area, wherein the first contact area in the area of the second housing side is connected to the inner housing wall or the second contact area in the area of the second housing side is connected to the outer housing wall.
 4. The heat exchanger according to claim 1, wherein the tubes are arranged substantially lying parallel next to one another in the longitudinal direction such that gaps, through which a coolant is adapted to flow, are formed between the tubes.
 5. The heat exchanger according to claim 1, wherein the first contact side and/or the second contact side and/or the first contact area and/or the second contact area are connected to the inner housing wall and/or the outer housing wall by soldering or welding.
 6. The heat exchanger according to claim 1, wherein the first contact side and/or the second contact side and/or the first contact area and/or the second contact area are connected to the inner housing wall and/or the outer housing wall substantially by material bonding.
 7. The heat exchanger according to claim 1, wherein the first tube ends in the area of the first through-openings are connected to the first tube sheet by soldering or welding and the second tube ends in the area of the second through-openings are connected to the second tube sheet by soldering or welding.
 8. The heat exchanger according to claim 1, wherein the first through-openings and/or the second through-openings each have passages through which the first tube ends and/or the second tube ends extend.
 9. The heat exchanger according to claim 1, wherein the housing has an inlet opening for a coolant supply and/or an outlet opening for coolant removal.
 10. The heat exchanger according to claim 1, wherein the tubes are formed as flat tubes, and/or turbulence inserts and/or spacers and/or corrugated fins are arranged between the tubes, and/or wherein the tubes have a substantially smooth surface and/or a substantially circular cross section.
 11. The heat exchanger according to claim 1, wherein the first tube sheet and/or the second tube sheet are produced in a deep-drawing process.
 12. The heat exchanger according to claim 1, wherein a bypass channel is located in an area of the housing.
 13. The heat exchanger according to claim 1, wherein the heat exchanger is an exhaust gas heat exchanger or a charge air cooler for a motor vehicle. 